Electric spray gun for shellac, paints, etc.



EL A. STECKEL, JR., ET AL 2,068,205

ELECTRIC SPRAY GUN FOR SHELLAC, PAINTS, ETC

Jan. 19, 1937.

4 Sheets-Sheet 1 Filed Sept. 16, 1955 Jan- 19, 1937- E. A. sTEcKEL, JR.. ET AL 2,068,205V

ELECTRIC SPRAY GUN FOR SHELLAC, PAINTS, ETC

'Filed sept. 16, '1955 4 sheets-sneet 2 Jan. 19, 1937.

E. A. STECKEL, JR.. ET AL ELECTRIC SPRAY GUN FOR SHELLAC, PAINTS, ETC

Filed Sept. 16, 1955 4 Sheets-Sheet 3 WMTTORNEY.

Y AJan. 19, 1937. EMEA sTEKEL, JR, ET AL 2,068,205

ELECTRIC kSPRAY GUN FOR SHELLKC, PAINTS, ETC

Filed sept.' 1e, 1935 4 sheets-sheet 4l Patented Jan. 19, 1937 UNITED STATES PATENT oFricE,

ELECTRIC SPRAY GUN-l"OR SHELLAC, PAINTS, ETC.

I` Elmer A. Steckel, Jr., and Elmer H. Bridenbaugh, Denver, Colo.; said Bridenbaugh assigner to said Steckel Application september 1s, 1935, serial No. 40,135

9 Claims.

. eflcient, electrically operated sprayer, in which all blowers, pumps, air hoses, etc., will be eliminated, which will produce its own pressure for atomizing and blowing the fluidywhich -can be minutely and accurately controlled, operated and used with a single hand; and which can be plugged into any convenient electric outlet for instant use.

Another object of the inventionis to provide a process for spraying surface coating material in which the pressure for the spraying operation is obtained by volatilizing the solvent of the coating material so that the use of foreign fluids or additional fluids is avoided.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency.

Fig. 1 is a perspective view of the complete invention as it would appear in use.

Fig. 2 is a vertical, longitudinal section therethrough illustrating the operating parts, the section being taken on the line 2 2, Fig. 4.

Fig. 3 is a detail horizontal section taken on the line 3 3, Fig. 4.

Fig. 4 is a lateral section taken on the line 4 4, Fig. 2.

Fig. 5 is a detail enlarged longitudinal section through the spray nozzle and pump head illustrating construction thereof.

Fig. 6 is a side elevation of an alternate form of the invention.

Fig. '7 is avertical section through the alternate form of Fig. 6.

Fig. 8 illustrates an alternate form of spray nozzle provided with cooling fins.

The invention comprises a generating dome I0 from which two removable jars I I and I2 are suspended. The jars II and I2 are threaded into a cap member I3 which in turn is secured to the bottom of the dome I8 by 5means of a suitable at' tachment screw I4 and an attachment bushing 56. The jar I2 is designed to hold the shellac,

paint, or other liquid to be sprayed. The jar II contains the solvent or uid to be vaporized for furnishing the operating pressure, such as alcohol, oil, water, etc.

The liquid is forced from the jar I2 by air pressure furnished by means of an air pump contained within a pump cylinder I5. Within the pump cylinder I5 is a pump piston I6 mounted for limited movement upon alpiston rod I1 which extends through the rear of the cylinder I5. The 1'05 piston rod I1 is moved forwardly, to compress air` in the forward end of the cylinder I5, by -means of a spring I8 which surrounds the piston rod I1. It is moved rearwardly against the action of the spring I8 by means of a pump handle I9 which is 1'5 connected through the medium of a pump rod 28 with a yoke 2l clamped on the rear extremity of the piston rod I1. The handle I9 is slidably mounted on the pump cylinder I5 so that it may move freely therealong. 20

The piston rod I1 is allowed a limited movement in the piston I6 so that on the forward or spring-actuated stroke a valve washer 51 will be forced against a seat 51' on the back of the piston to seal the latter, and on the rearward or manually-actuated stroke the valve washer will move away from the seat 51 on the piston to allow air to flow through the piston to the head of the cylinder.

The compressed air from the front of the cylin- 30:

der I5 is conducted by means of a conduit 24 into the upper part of the jar I2, to force the paint or other fluid therefrom through a discharge pipe 25. The air also flows from the front of the pump' cylinder through a second conduit 26 into the 3'5"- cap at the top of the solvent jar II, to force the solvent therefrom through a. discharge pipe 21.

The forward extremity of the pump is provided with a check valve 28 which is forced against a discharge port 29 by' means of a spring 30 to 4U' act as a check valve. The air from the pump forces this check valve open and the spring 30 forces it closed to prevent pressure in the jars II and I2 from returning air to the pump. The

solvent pipe 21 is also protected by a ball check 45 valve 58 to prevent the pressure in the dome |0` from entering the jar II.

The vaporizing dome I 0 is provided with an electrical heating element 3| surrounded by a protecting cap 32. Current is supplied to the 50.`

element through a suitable conductor 18. The cap in turn is surrounded by a guide sleeve 33. The solvent from the pipe 21 flows into a head chamber 34`1n the dome and from thence through the guide sleeve 33 around the hot cap 32. It 55 dome I0. The highly heated and vaporized condition of the solvent creates considerable pressure in the dome I0, and a safety valve 35 is provided to relieve excess or dangerous pressures therefrom.

'I'he exit of the vaporized solvent from the dome II) is controlled by a needle valve 36 which acts to" close a valve seat member 31 in the side of the dome I IJ. A passage 38 leads from the valve seat member 31 to the interior of a spray nozzle shell 39. The spray nozzle shell is clamped in place by means of a clamping bushing 19 so that it may be easily removed for replacement or repairs.

'Ihe pump cylinder I5 supports a handle frame 22 at the rear of the device from which a suitable hand grip 23 projects downwardly. The needle valve 36 is operated from a trigger 40 positioned on the handle frame 22 convenient to the thumb of the operator. 'I'his trigger is connected through a link 4I with an equalizing lever 42, the upper extremity of which is bifurcated to flt over the needle valve 36. A spring sleeve 43 is secured to the needle valve 36 to form a pressure surface for the equalizing lever 42. A compression spring 44 acts to return the needle valve to its seat. f

The spray nozzle shell 39 is provided with a discharge oriilce 45 and encloses an inner member"46. The inner member acts as a stop or seat for the shell 39 to hold the latter in proper electing relationship with a passage 41 from which the fluid being sprayed discharges. This relationship creates a vacuum to project the :duid

from the pipe 25 through the orifice 45 in the Shell 39.

'I'he pipe 25 communicates with a feed chamber 48 to the rear of the inner member 46. The flow from the chamber 48 through the nozzle is controlled by means of a second needle valve 49 which acts against a seat in the passage 41. The second needle valve 49 is also operated by the equalizing lever 42 from the trigger 48. A spring sleeve 50 encloses the second needle valve and acts as a pressure surface for the equalizing lever 42 and also as a step for a compression spring 5I, which constantly urges the needle valve 49 to its seat.

To relieve the pressure in the jars II and I2 when desired, a valve rod 53 is provided. v 'I'his rod extends axially through the hollow piston rod I1 and projects beyond the forward extremitythereof, terminating in a valve washer 54. 'I'he valve washer is constantly held against the head of the piston rod by means of a compression spring 55. When the rod 53 is pushed forwardly, its forward extremity will force the check valve 28 from its seat, allowing the pressure in the jars to return through the valve passage 29 and through the hollow piston rod I1 to the atmosphere.

Let us assume that the device is to be used for spraying shellac with an alcohol solvent. 'I'he alcohol is placed in the jar II and liquid shellac is placed in the jar I2. 'I'he electrical current is turned into the heating element 3|. This current heats the element 3l, the enclosing cap 32, and the sleeve 33 to a temperature suiilciently high to vaporize the solvent. The operator holds the device in one hand by means of the grip 23, and with his foreiingers pulls the pump handle I9 rearwardly. He then releases the handle, I9 allowing the spring I8 to exert a forward pressure on the piston I 6. 'I'he spring pressure places a predetermined air pressure in the top of both jars II and I2. The pressurel in the jar II forces the solvent into the generating dome where it is immediately vaporized to create vapor pressure in the dome. The pressure in the jar I2 forces the liquid to be sprayed into the feed chamber 48 of the spray nozzle. The operator now presses the trigger 40 with his thumb.

It is desired to call attention to the fact that the link 4I is connected off center on the lever 42 so that a greater leverage is exerted on the needle valve 36'than on the needle valve 49. Therefore the initial pressure on the trigger 40 acts to open the needle valve 36, allowing the high pressure vaporized solvent to flow to the atomizing nozzle. Further pressure in the trigger 4I) opens the needle valve 49, allowing the paint or other fluid to be drawn into the vaporizing nozzle and forced therefrom in a line atomized spray. 1

The amount that the needle valve 36 opens can be regulated by the setting of a stop screw 16 provided with a suitable lock nut 11. The extremity of the screw 'I6 contacts with-the extremity of the needle valve 36 to. limit its maximum opening. A similar stop is provided for the needle valve 49 comprising a stop screw 52, the extremity of which acts to contact the rear oi' the needle valve 49 and limit the maximum opening thereof. If desired, an alternate form of spray nozzle bushing, such as shown in Fig. 8, provided with cooling fins 19, may be provided to cool the nozzle shell 39.

It is desired to call attention to the fact that a predetermined pressure in the dome I0 will prevent the spring I8 from forcing fluid past the check valve 58 so that an automatic control is had to prevent excess fluid from reaching the heating element.

In Figs. 6 and 7, an alternate form of the inventlon is'shown comprising a frame member 65 supporting a downwardly projecting reservoir 66, which carries the solvent or other pressuresupplying fluid, andalso serves as a handle for supporting the device in the hand. The frame member 65 also supports a container 59` for the material to be sprayed and a pressure chamber or vaporizing dome 68.

A suction pipe 6I extends downward into the container 59 from a lower atomizing tip 62. A vapor pipe 63 extends from the Vtop of the vaporizing dome to an upper atomizing tip 64.

A heating chamber 61 extends downwardly from the vaporizing dome 6U and contains an electrical heating element 68 to which current is fed by means of suitable conductors 69. A pump cylinder 10 is formed in the frame 65 in which a pump piston 1I is reciprocated on the return stroke by means of a manual trigger 12 and on the compression stroke' by means of a compression spring 13.

As the piston 1I moves outwardly, it will draw solvent from the tube 66 through a tube 14 and as it moves forwardly, the spring 13 will force the solvent past a check valve 15 into the heating chamber 61. 'I'he element 68 will immediately vaporize this fluid, creating a pressure in the container 68 which will actuate the atomizing tips 62 and 64. In this form of the device there is no control of the vapor pressure to the atomizer. 'Ihe entire control is accomplished by regulating the amount of solvent pumped to the vaporizing chamber 61.

It is desired to call attention to the factthat 75' since a volatile solvent for the material being sprayed is employed as the pressure .supplying medium, the material is not harmed in any Way. 'I'he vaporized solvent forms a perfect solution with the material leaving a'perfect, uniformy coating after evaporation.

While a specific form of the improvement has been described and illustrated herein, it is de'- sired to be understood that the same may be varied within the scope of the, appended claims, without departing from the spirit of theinvention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:- l

1. A sprayer for spraying a first fluid by vaporizing a second fluid comprising: a generating compartment; a first container for said first fluid; a second container for said second fluid; an electrical heating element in said compartment; an atomizing nozzle; means for conducting said first fluid to said nozzle; means for forcing said second fluid into said compartment so that it will be vaporized by said heatingv element to create a pressure; and a conduit for conducting the vaporized second fluid from said compartment to said nozzle for spraying said first i fluid from said nozzle.

2. A sprayer for spraying a first fluid by vaporizing a second fluid comprising: a generating compartment; a first container for said first fluid; a second container for said second fluid; an electrical heating element in said compartment; an atomizing nozzle; means for conducting a rst fluid to said nozzle; and means for forcing said second fluid into said compartment so that it will be vaporized by said heating element to create a pressure; a conduit for conducting the vaporized second fluid from said compartment to said nozzle for atomizing said first fluid at said nozzle; a valve for controlling the discharge of the vaporized second fluid; a second valve for controlling the discharge of said first fluid.

3. A sprayer for spraying a first uid by vaporizing a second fluid comprising: a generating compartment; a first container for said first fluid; a second container for said second fluid; an electrical heating element in said compartment; a sprayingnozzle; means for conducting a first fluid to said nozzle; means for forcing said second fluid into said compartment so that it will be vaporized by said heating element to create a pressure; a conduit for conducting the vaporized second fluid from said compartment to said nozzle for spraying said first fluid from said nozzle; a valve for controlling the discharge of the vaporized second fluid; a second valve for controlling the discharge of said first fluid; and a trigger for operating said valves, said trigger being arranged to open said first valve prior to the opening of said second valve.

4. A sprayer for spraying a first fluid by vaporizing a second fluid comprising: a generating compartment; a first container for said first fluid; a second container for said second fluid; an electrical heating element in said compartment; an atomizing nozzle; means for conducting a first fluid to said nozzle; and means for forcing said second fluid into said compartment so that it will be vaporized by said heating element to create a pressure; a conduit for conducting the vaporized second fluid from said compartment to said nozzle for atomizing said first fluid at said nozzle, said means comprising: an air pump; and a conduit for conducting the air therefrom to said containers.

5. A sprayer for 'spraying a first fluid by vaporizing a second fluid comprising: a generating dome; a cap member suspended from said dome;

a pair of containers supported from said cap member; an electrical heating element in said dome; an air pump; means for conducting air from said pump to said containers for creating a pressure in said containers; a spray nozzle; a first conduitv from one of said containers to said nozzle; a second conduit from the other of said containers to said dome; and a third conduit Y from said dome to said nozzle so that pressure from the former will actuate the latter.

6. A sprayer for spraying a first fluid by vaporizing .a second fluid comprising; a generating dome; a cap member supported from said generating dome; a first container for said first fluid supported from said cap member; a second container for said second fluid supported from said cap member; a spray nozzle; a. first conduit from said first container to said nozzle; a second coned from said cap member; a second container for said second fluid supported from saidcapmember; a spray nozzle; a first conduit from said first container to said nozzle; a second conduit from said dome to said nozzle; a third conduit from said second container to said dome; an electrical heating element in said dome; a pump cylinder projecting rearwardly from said cap member and comvdome; a first container for said first fluid supportmunicating at its forward extremity with said containers; a hand grip projecting downwardly from the rearward extremity of said pump cylinder; a piston in said cylinder; a spring for forcing said piston forwardly to create apressure in said containers; a handle adjacent said hand grip for moving said piston rearwardly; and means for controlling the flow through said first and second conduits.

8. A sprayer for spraying a first fluid by vaporizing a second fluid comprising: a. generating dome; a cap member supported from said generating dome; a first container for said first fluid supported from said cap member; a second container for said second fluid supported from said cap member; a spray nozzle; a first conduit from said first containerto said nozzle; a second conduit from said dome to said nozzle; a third conduit from said second container to said dome; an electrical heating element in said dome; a pump cylinder projecting rearwardly from said cap member and communicating at its forward extremity with said containers; a hand grip projecting downwardly from the rearward extremity of said pump cylinder; a piston in said cylinder; a spring for forcing said piston forwardly to create a pressure in said containers; a handle adjacent said hand grip for moving said piston rearwardly; a first needle Valve for controlling the flow from said dome through said second conduit; a second needle valve for -controlling the flow from said first container through said firstl 9. A sprayer for spraying a first fluid by vaporizing a second fluid comprising: a generating dome; a cap member supported from said generating dome; a rst container for saidrst fluid' supported from said cap member; a second container for said second fluid supported from said cap member; a spray nozzle; a rst conduit from said rst container to said nozzle; a second conduit from said dome to said nozzle; a third conduit from said second container to said dome; an electrical heating element in said dome; a pump cylinder Yprojecting rearwardly from said cap member and communicating at its forward extremity with said containers; a hand grip projecting downwardly from the rearward extremity of said pump cylinder; a piston in said cylinder; a spring for forcing said piston forwardly to create a `pressure in said containers; a handle adaoeaaos y jacent said hand grip for moving said piston rearwardly; a first needle valve for controlling the ow from said dome through said second conduit; a second needle valve for controlling the iiow from said rst container through said first conduit, said needle valves projecting rearwardly to a position adjacent said hand grip; and a trigger mounted adjacent said hand grip for operating said needle valves; an equallzing lever extending between said rearwardly projecting needle valves; and a link connecting said lever to said trigger, the connecting point of said link being eccentric of said lever so that said rst needle valve will open in advance of said second needle valve.

ELMER A. STECKEL, JR.

ELMER H; BRIDENBAUGH.

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